Silicon carbide (SiC) and other ceramic materials are used to produce articles having high structural and mechanical strength at a temperature above 1,200° C. (2,200° F.). The articles are commonly used in aerospace and other industries needing resistance to heat. As operation temperatures increase above 1,200° C., material options for the articles decrease exponentially because metal and metal alloys are not viable. While ceramic matrix composites (CMCs) and carbon-carbon (C—C) materials are conventionally used at these temperatures, these materials are expensive and time intensive to produce. Processing of the CMCs and C—C materials requires multiple heat treatments and processing acts to densify the materials and provide the desired strength. Producing CMCs requires several infiltration cycles, which increases the overall cost and amount of time to fabricate the CMCs. Additionally, conventional furnaces used to produce the articles are not sufficiently large to accommodate large articles, such as those needed for large rocket motors.
One method of forming SiC and other ceramic materials is from preceramic polymers. However, conventional preceramic polymers, such as polycarbosilanes, have a low viscosity (less than about 200 cP), which limits their practical use in the preparation of CMCs where the preceramic polymer provides the matrix of the CMC. One commonly-used preceramic polymer is polycarbosilane. However, the polycarbosilane has limited use due to its low viscosity and extensive cracking after curing at, for example, 121° C. (250° F.). Additionally, the ceramic materials formed from conventional preceramic polymers exhibit high mass loss, extensive cracking at low temperature (less than about 121° C.), high porosity, and high shrinkage. Cracking of the ceramic material is worsened as high loading of fillers is needed, rendering the ceramic material formed from the conventional preceramic polymers ineffective. Viscosity modifiers or cracking mitigation additives have been used with conventional preceramic polymers. However, with the modifiers or additives, a low ceramic yield is observed at a temperature greater than about 816° C. (about 1500° F. Polycarbosilane has also been combined with a polysiloxane, such as polydimethylsiloxane, to improve its viscosity. However, the ceramic yield of the resulting ceramic material was unacceptably low.